The magnum does not do more damage all the time. The bullet is what does the damage. The worst blown to hell deer I ever saw was hit with a 140 grain Speer Hot core bullet from a 280. Bullet weight and type have more to do with damage than velocity. Any animal hit right with almost any caliber is going to go down in short order. I have killed deer with calibers from 22 rimfire to 416 Rem Mag and 45-70.